<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            padding: 0;
            margin: 0;
        }

        body,
        .nav1,
        .nav2 {
            margin-bottom: 20px;
        }

        .nav1 {
            width: 300px;
            height: 100px;
            border-radius: 50px;
            /*border-radius 圆角边框 */
            border: 2px solid red;

        }

        .nav2 {
            width: 280px;
            height: 150px;
            background-color: pink;
            border-radius: 50px;
        }
    </style>
</head>

<body>
    <div class="nav1"></div>
    <div class="nav2"></div>
</body>

</html>